Trivia

In the Chinese version of the game, Xin Zhao's name is rendered as Zhao Xin (赵信), as Chinese names are written with their family name first. In Traditional Chinese and in Japanese, the name would be written as 趙信, while being pronounced as "Choushin" via on'yomi.

His name Xin (信) means "faith" or "trust" in Chinese.

"Zhao" in Chinese is a unique character, only usable as a last name. However, it is mainly due to being written in Simplified Chinese. The Traditional version of the character is written as 趙, which can also be used in Japanese, which literally means "nimble".

General

Xin Zhao is the only champion that references Asian culture but does not belong to Ionia.

Xin Zhao's joke is a reference to the question, "What happens when an unstoppable force meets an immovable object?" This in turn is a reference to the Chinese word Maodun, 矛盾 (lit. spear and shield) which means "Contradiction".

Coincidentally, Richard Epcar, Xin Zhao's voice actor, has done a few roles in the Koei Warriors franchise, namely Shingen Takeda in the first Samurai Warriors game and its expansion, but more so Dong Zhuo ever since Dynasty Warriors 4.

Xin Zhao can be seen fighting Baron in the background of his splash art.

Xin Zhao's appearance is very much alike to the CCG Investigators from the anime series Tokyo Ghoul, so much that even his spear transforms into a suitcase, like an investigator's quinque.

Also in splash art his appearance looks like Adam Jensen from Deus Ex franchise.

He wields the Mark-VII, clandestine-class, utili-spear. Equipped with the latest in communications technology and palmprint identification software, this protean pike’s a repository of sophisticated tools and gadgets for the modern day secret agent. It’ll enhance the users spycraft with everything from garden-variety lockpicks to a microprocessor that coordinates ganks in seven hundred languages (including whatever the hell it is that Gnar yowls). But it’s mostly used for poking people with it.[1]

The 3D model has him wear a handsfree mobile device which is missing from the splash art.